Dental broach.



PATENTED DEC. 10,- 1907.

0'. A. SKALSTAD. DENTAL BROAOH.

APPLIGATION FILED JAN.10, 1907.

Q B. M r a m w w 0 c s R s 1 s P m R P n n E n 1 CARL A. SKALSTAD, OF CHICAGO, ILLINOIS.

DENTAL BROACH.

Specification of Letters Patent.

Patented Dec. 10, 1907'.

Application filed Jan ary 10, 1907- Serial No. 351.582.

To all whom it may concern:

Be it known that I, CARL A. SKALSTAD, a citizen of the United States of America, and resident of Chicago, Cook county, Illinois, have invented a certain new and useful Improvement in Dental Broaches, of which the following is a specification.

My invention relates to improvements in dental instruments, especially drills, burs, broaches and reamers, and has for its object the production of a device by means of which the operator may readily work in root canals, whether such canals extend directly upwardly or downwardly, or at an angle thereto.

The further object is the production of a device that is simple in construction, and one in which the removable parts thereof may be readily removed and others substituted with the least possible delay.

The further object is the production of a cheap and eflicient instrument, and one that comprises the fewest possible parts, and is least liable to get out of order.

These and such other objects as may hereinafter appear are attained by my device, embodiments of which are illustrated in the accompanying drawings, in which Figure 1 represents a sectional view on the line 11 of Fig. 2, looking in the directionindicated by the arrows, and showing a broach in position for operation. Fig. 2 is a front elevation of Fig. 1. Fig. 3 is a perspective view of a modification of my device whereby the orking tool is place .in an angular position. Fig. 4 is a vie" of the modification illustrated in Fig. 3, with the position of the working tool reversed.

Like letters of reference indicate like parts in the several figures of the drawing.

Referring now to the drawings, 5 represents an outer casing or sleeve formed either of metal, hard rubber, or any similar substance.

6 represents the shaft of the tool holder which is cut away at 7 in order to reduce the weight, leaving, however, its upper end 8 fitting snugly within the sleeve, and the lower end 9 also fitting within the sleeve. The lower end of the shaft terminates in a handle 10 outside of the sleeve, which is preferably burred or roughened by means of which the shaft may be turned within the sleeve. The outer end of the shaft is provided with a bevel gear 11, which is adapted to mesh with the bevel gear formed on the tool holder used. In the lower part 9 of the shaft an annular groove 12 is formed and a leaf spring 13 is attached on the outer side of the sleeve. This leaf spring carries a pin 14 which enters an opening 15 in the sleeve, the end of the pin extending into the said groove 12, thereby locking the shaft in place, but permitting it to rotate within the sleeve. Of course there are other means by which the shaft could be held in position, but I find the above method simple and efficient.

The upper end of the sleeve terminates in an car 16, integral with or secured thereto, and extending at any desired angle therefrom. In Fig. 1 the ear 16 extends along the same line as the sleeve itself, and has an opening 17 therein within which is seated the head or tool-holder 18 for the broach or other point used. The tool holder shown in Fig. 1 is provided with a head 18 and a bevel gear 19 meshing with the bevel gear 11 on the main shaft. A nerve broach 20 is shown extending at right angles to the hand-piece and firmly seated in the head 18.

In Fig. 3 the car 21 is shown extending at an angle to the sleeve. The head 22 of the broach is seated within thelear and the bevel gear 23 meshes with the gearing 24 on the main shaft. is disposed at an obtuse angle to the hand piece, the gearing being beveled atthe proper In this position the broach 25 angle in order to provide for eflicient working of the parts.

In Fig. 4 the bevel gear 26 is shown as opposite to that illustrated in Fig. 3, thus insuring the proper meshing with the gearing 24. In this embodiment the broach 25 extends at an acute angle to the hand piece.

Referring now to the operation of my device, the proper point, either the broach, bur or reamer is slipped within the ear, the spring holding the main shaft in position having been pulled outwardly allowing the shaft to be retracted. The shaft is then pushed in place the bevel gear on the shaft meshing with the bevel gear on the head holding it securely in place. The revolution of the shaft by means of the handle 10 consequently rotates the point 20. It will be noted that by use of the modification shown in Figs. 3 and 4, it will be a simple operation to work within root canals that in many instances extend at a considerable angle from the perpendicular. Heretofore it haslbeen quite a difficult operation to do this, as the space within which the operator may work is extremely limited, and in the use of the ordinary form of instrument it has been a somewhat diflicult operation to Work in root canals other than those extending vertically, and has rendered it necessary for the operator to work in a very awkward position in order to do eflicient work. By the use of the modification shown, however, it is as easy to work in the diagonal channels as in the vertical, by simply changing the form of instrument. I do not limit myself to any particular angle of gear, as every well equipped office will be provided with instruments of different angles whereby the operator may adapt himself to the different circumstances of individual cases. By the use of my improvement operations which have heretofore been very difiicult are rendered now very simple, with the consequent saving of time of both the operator and the patient.

I claim:

1. As a new article of manufacture, a dental tool comprising a slotted sleeve, having an ear extending from the end of said sleeve integral therewith, a shaft fitting Within said sleeve, and terminating in a bevel gear, a tool holder seated in said ear, and means for bringing said tool holder into operative engagement with said bevel gear.

2. As a new article of manufacture, a dental instrument comprising a slotted sleeve, an ear extending from the end thereof, a shaft provided with an annular groove fitting within said sleeve, said shaft terminating in a bevel gear, a removable tool holder provided with a bevel gear in operative engagement with the gear on said shaft, means for holding said shaft removably in place, said means comprising a spring secured to said sleeve, a pin carried thereby, said pin being so positioned as to pass through the slot in said sleeve and into the annular groove in said shaft.

Signed by me at Chicago, Illinois, this 5th day of January 1907 CARL A. SKALSTAD.

Witnesses:

S. LEWIS, ALBERT JorIN SAUSER.

Correction in Letters Patent No. 873,100.

It is hereby certified that in Letters Patent No. 873,100, granted December 10, 1907, upon the application of Carl A. Skalstad, of Chicago, Illinois, the title of the invention was erroneously written and printed Dental Broaohes, whereas the said title should have been Written and. printed Dental Breach-Holders and that the proper corrections have been made in the files and records of the Patent Ofliee, and are hereby made in said Letters Patent.

Signed and sealed this 14th day of January, A. D., 1908.

[SEAL] o. o. BILLINGS,

Acting Commissioner of Patents. 

